Strange and unstable behavior of IFS PrintServer

I have a customer using IFS PrintServer for label printing.
The PrintServer loses the connection to database every night but don't restart even the configuration is done. Because I started the PrintServer as normal process I'm able to see the error message "connection lost, reconnect?". When clicking on Yes it will reconnect to the database and starts spooling/fetching printouts again. However the PrintServer won't find the prints waiting in the print queue. Only restarting the process will help.

Does anybody know why the PrintServer is behaving like this?
What can I do to troubleshoot this?

I didn't find any useful information in Knowledge Search, in IFS Apps Change Logs , Log files or anywhere else.

Even worse, when the customer is using the Service wrapper ifssvr.exe to run PrintServer as service, the service needs to restarted up to 6 times a day to proceed with printing.

The customer is using IFS Apps 7.5 CPS2 in production.